1. Field of the Invention
The present invention relates to a communications device and, more particularly, to a cellular portable radiotelephone having improved operability.
2. Description of the Prior Art
In recent years, cellular portable radiotelephones are widely developed that transmit a signal, which is input in the form of a voice, to a telephone exchange in the form of a radio wave, and output a signal, which is received from the telephone exchange in the form of a radio wave, in the form of a voice.
A cellular portable radiotelephone of this type includes, in its housing, a telephone receiving section having a loudspeaker for converting an electric signal into a voice, and a telephone transmitting section having a microphone for converting a voice into an electric signal. A key operating section having a dialing function, an LCD display, and the like are also provided to the cellular portable radiotelephone.
In the conventional cellular portable radiotelephones, for example, one in which part of its housing is foldable (e.g., Japanese Unexamined Patent Publication No. 4-117848), one in which part of its housing is slidable (e.g., Japanese Unexamined Patent Publication No. 4-273744), and the like are proposed.
FIG. 1 is a perspective view of a conventional foldable cellular portable radiotelephone. In the cellular portable radiotelephone shown in FIG. 1, a telephone receiving section 23 is arranged in an upper housing 21, and a telephone transmitting section 24 and a key operating section 25 are disposed on a lower housing 22. The upper housing 21 and the lower housing 22 are pivotally coupled to each other through a hinge 26.
FIGS. 2A and 2B are plan and sectional views, respectively, showing a conventional slidable cellular portable radiotelephone. In the cellular portable radiotelephone shown in FIGS. 2A and 2B, a telephone receiving section 23 is arranged in an upper housing 21, and a telephone transmitting section 24 and a key operating section 25 are disposed in a lower housing 22. The lower housing 22 is coupled to the upper housing 21 to be slidable substantially parallel in directions indicated by a two-headed arrow in FIG. 2B.
In the conventional foldable cellular portable radiotelephone, the upper housing 21 and the lower housing 22 must be opened apart before operation, which is cumbersome. In the conventional slidable cellular portable radiotelephone, since the operation surface is always exposed to the outside, an erroneous operation of or damage to the device is likely to occur.